Delia Martin has been gifted (or some would say cursed) with the ability to peer across to the other side. Since childhood, her constant companions have been ghosts. She used her powers and the help of those ghosts to defeat a twisted serial killer terrorizing her beloved San Francisco. Now it's 1917—the threshold of a modern age—and Delia lives a peaceful life with Police Captain Gabe Ryan.

That peace shatters when a strange young girl starts haunting their lives and threatens Gabe. Delia tries to discover what this ghost wants as she becomes entangled in the mystery surrounding a charismatic evangelist who preaches pacifism and an end to war. But as young people begin to disappear, and audiences display a loyalty and fervor not attributable to simple persuasion, that message of peace reveals a hidden dark side.

As Delia discovers the truth, she faces a choice—take a terrible risk to save her city, or chance losing everything?